According to the difference between flight test operation and civil aviation flight operation, how to choose the flight test alternate airport was analyzed and studied. By summarizing the ex-perience of flight test organization of certain type of aircraft, and combining with the civil aviation dispatch as regards the alternate airport and the characteristics of civil aircraft flight test operation support, the civil aircraft flight test alternate airport support conditions assessment method and the flight test alternate airport selection method are proposed, which lays a foun-dation for improving the flight test safety and flight test FOC system.